Adaptive voltage over-scaling for resilient applications

We present an energy-reduction strategy for applications which are resilient, i. e. can tolerate occasional errors, based on an adaptive voltage control. The voltage is lowered, possibly beyond the safe-operation region, as long as no errors are observed, and raised again when the severity of the detected errors exceeds a threshold. Due to the resilient nature of the applications, lightweight error detection logic is sufficient for operation, and no expensive error recovery circuitry is required. On a hardware block implementing texture decompression, we observe 25% to 30% energy reduction at negligible quality loss (compared to the error introduced by the lossy compression algorithm). We investigate the strategy´s performance under temperature and process variations and different assumptions on voltage-control circuitry. The strategy automatically chooses the lowest appropriate voltage, and thus the largest energy reduction, for each individual manufactured instance of the circuit.